Commercial HVAC systems Flashcards
In commercial hvac systems, there are two types of HVAC systems
Constant air volume (CAV)
Variable air volume (VAV)
In a simple constant air volume system, the supply air flow rate is (…)?
Is constant, but the supply air temperature is varied to meet the thermal loads of a space.
What does most CAV systems serve
Small and serve a single thermal zone.
What does CAV stands for
Constant Air Volume
The two types of CAV systems that are commonly used to modify the supply air temperature?
The terminal reheat system
The mixed air system
Disadvantage of terminal reheat system.
Waste energy
Mixed air volume system.
Has two air streams, one for the coldest and one for the hottest. The two air streams are strategically combined to offset the space load .
Hot and cold air never mixes in the three-deck system. (True or False)
True
What is the difference between a multi zone system and a three deck multi zone system ?
Unlike the multi zone system, a three deck multi zone system a neutral air stream that is neither cooled or heated. In this system the cool and hot air never mixes, eliminating energy waste !
Where does the air mixing occur in a dual duct system?
In the zone or close to the zone it is serving
Where does the air mixing occur in a multi zone system?
Mixing occurs in the air handling unit.